What events will trigger a notification onto the user's news feed?

We've been holding off implementing integration with Facebook's news feed until they finalize their new roadmap. They are pretty close to doing so now and we hope to add these features in soon.

All over our site, users can use Share+ links to put content on their wall or share with others.

Soon, we'll add integration with Facebook's dashboard API and its stream API to provide deeper integration into the news feed.
http://wiki.developers.facebook.com/index.php/Roadmap_Dashboards